Force sensors are known, for example, from U.S. Pat. No. 6,002,090.
A drawback of this type of force sensor is that it does not provide protection against excessively large forces acting thereon. As a result, excessively large forces or an overload can destroy the force sensor. Furthermore, if the overload is very large, the spring element can shear or tear off completely, such that the force sensor no longer provides a mechanical connection between the screwed-down force input elements.
For example, if a seat in a passenger car is connected to the chassis so that the weight load of the seat can be measured, the shearing-off of the connecting spring elements (typically four in number) in the event of a crash would have the result that the seat is no longer connected to the chassis. This, however, must be prevented under all circumstances, if possible. The term overload protection as used below should thus be understood to mean both the protection of the force sensor itself in the event of relatively small overloads and the protection against tear-out or complete shearing of the items fastened via the force sensor in the event of large overloads. In the conventional force sensor, an overload protection of this type must be provided outside the force sensor by a corresponding configuration of the mounting environment, which is often difficult and costly to implement.